Issues with complex HTML in API calls

I’m just starting to use the API to create a new Marketing email campaign. I can get it to work if I simply use the « Hello World » text, but when I use a more complex html page, I get a 403 error with no extra error information, so I dont know what its complaining about.
Are there any case studies or « real world » examples that will help me work out what’s going wrong?
for example is there a syntax checker for the HTML that I can use to test the HTML, or does the total request need to be json string compliant?
TIA

Hi @pdrage , do you still face the same issue?

Hi Alexandre,

I think in this instance, I may have found that the answer is that I have. tag in my html.

If that is the case, then it was yod help if the API told me so rather than throwing a permission exception.

Are there any other rules that I need to be aware of?

Paul.

Indeed, thanks for the feedback. I guess @Mauricio you’ll be interested in this thread as well.

About the rules, I have to admit, I’m not a master of this topic, so hard for me to reply.

Indeed, thanks for the feedback. I guess @Mauricio you’ll be interested in this thread as well.

About the rules, I have to admit, I’m not a master of this topic, so hard for me to tell you?